Potassium (K plus ) gradients serve as a mobile energy source in plant vascular tissues
Potassium (K plus ) gradients serve as a mobile energy source in plant vascular tissues
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DOI：
10.1073/pnas.1009777108
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发表时间：
2011-01-11
影响因子：
11.1
通讯作者：
Dreyer, Ingo
中科院分区：
文献类型：
--
作者：
Gajdanowicz, Pawel;Michard, Erwan;Dreyer, Ingo
钾（K+）是植物最重要的无机阳离子，是作物产量和品质的限制因子。尽管如此，K+对植物生产力的贡献仅部分了解。K+被用作主要的活性溶质以维持膨压并驱动细胞体积的不可逆和可逆变化。K+在许多代谢过程中也起着重要作用，例如，作为酶的重要辅因子。在这里，我们提供了一个额外的，以前未被认识到的K+在植物生长中的作用的证据。通过将不同的实验方法与计算细胞模拟相结合，我们表明，在韧皮部中循环的K+作为分散的能量储存，可用于克服当地的能量限制。韧皮部表达的拟南芥K+通道AKT 2的翻译后修饰利用这种“钾电池”，然后有效地协助质膜H+-ATP酶激活跨膜韧皮部（重新）加载过程。
The essential mineral nutrient potassium (K+) is the most important inorganic cation for plants and is recognized as a limiting factor for crop yield and quality. Nonetheless, it is only partially understood how K+ contributes to plant productivity. K+ is used as a major active solute to maintain turgor and to drive irreversible and reversible changes in cell volume. K+ also plays an important role in numerous metabolic processes, for example, by serving as an essential cofactor of enzymes. Here, we provide evidence for an additional, previously unrecognized role of K+ in plant growth. By combining diverse experimental approaches with computational cell simulation, we show that K+ circulating in the phloem serves as a decentralized energy storage that can be used to overcome local energy limitations. Posttranslational modification of the phloem-expressed Arabidopsis K+ channel AKT2 taps this "potassium battery," which then efficiently assists the plasma membrane H+-ATPase in energizing the transmembrane phloem (re) loading processes.